Ni-affinity purification and reducing agents

-- Fellow Readers
My question to the readers is concerning affinity-purification of recombinant
proteins, by use of Ni-NTA columns.
I've constructed and purified recombinant proteins of different kinds, but
I've run my head against a tedious problem. So far, I've used
beta-mercaptoethanol as a reducing agent, if the fusionprotein in question was
containing cysteine-residues. One drawback by using this reagent, is that it
binds covalently to the residues and thereby manipulating an antigenic property
of the fusionprotein.
My question is, can you use a reducing agent like DTT or DTE instead of
beta-mercaptoethanol. I've heard that it is not possible with Ni-NTA columns,
have anyone got experience with that ?
Is it maybe possible to remove beta-mercaptoethanol upon purification ?
Any comments or suggestions will be greatly appreciated
Regards
Per Mygind , Medical Microbiology , University of Aarhus , Denmark
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